Radiation

The principal risks associated with nuclear
power arise from health effects of radiation. This radiation consists
of subatomic particles traveling at or near the velocity of light---186,000
miles per second. They can penetrate deep inside the human body where
they can damage biological cells and thereby initiate a cancer. If they
strike sex cells, they can cause genetic diseases in progeny.

Radiation occurs naturally in our environment;
a typical person is, and always has been struck by 15,000 particles of
radiation every second from natural sources, and an average medical X-ray
involves being struck by 100 billion. While this may seem to be very dangerous,
it is not, because the probability for a particle of radiation entering
a human body to cause a cancer or a genetic disease is only one chance
in 30 million billion (30 quintillion).

Nuclear power technology produces materials
that are active in emitting radiation and are therefore called "radioactive".
These materials can come into contact with people principally through
small releases during routine plant operation, accidents in nuclear power
plants, accidents in transporting radioactive materials, and escape of
radioactive wastes from confinement systems. We will discuss these separately,
but all of them taken together, with accidents treated probabilistically,
will eventually expose the average American to about 0.2% of his exposure
from natural radiation. Since natural radiation is estimated to cause
about 1% of all cancers, radiation due to nuclear technology should eventually
increase our cancer risk by 0.002% (one part in 50,000), reducing our
life expectancy by less than one hour. By comparison, our loss of life
expectancy from competitive electricity generation technologies, burning
coal, oil, or gas, is estimated to range from 3 to 40 days.

There has been much misunderstanding on
genetic diseases due to radiation. The risks are somewhat less than the
cancer risks; for example, among the Japanese A-bomb survivors from Hiroshima
and Nagasaki, there have been about 400 extra cancer deaths among the
100,000 people in the follow-up group, but there have been no extra genetic
diseases among their progeny. Since there is no possible way for the cells
in our bodies to distinguish between natural radiation and radiation from
the nuclear industry, the latter cannot cause new types of genetic diseases
or deformities (e.g., bionic man), or threaten the "human race". Other
causes of genetic disease include delayed parenthood (children of older
parents have higher incidence) and men wearing pants (this warms the gonads,
increasing the frequency of spontaneous mutations). The genetic risks
of nuclear power are equivalent to delaying parenthood by 2.5 days, or
of men wearing pants an extra 8 hours per year. Much can be done to avert
genetic diseases utilizing currently available technology; if 1% of the
taxes paid by the nuclear industry were used to further implement this
technology, 80 cases of genetic disease would be averted for each case
caused by the nuclear industry.

Reactor accidents

The nuclear power plant design strategy
for preventing accidents and mitigating their potential effects is "defense
in depth"--- if something fails, there is a back-up system to limit the
harm done, if that system should also fail there is another back-up system
for it, etc., etc. Of course it is possible that each system in this series
of back-ups might fail one after the other, but the probability for that
is exceedingly small. The Media often publicize a failure of some particular
system in some plant, implying that it was a close call" on disaster;
they completely miss the point of defense in depth which easily takes
care of such failures. Even in the Three Mile Island accident where at
least two equipment failures were severely compounded by human errors,
two lines of defense were still not breached--- essentially all of the
radioactivity remained sealed in the thick steel reactor vessel, and that
vessel was sealed inside the heavily reinforced concrete and steel lined
"containment" building which was never even challenged. It was clearly
not a close call on disaster to the surrounding population. The Soviet
Chernobyl reactor, built on a much less safe design concept, did not have
such a containment structure; if it did, that disaster would have been
averted.

Risks from reactor accidents are estimated
by the rapidly developing science of "probabilistic risk analysis" (PRA).
A PRA must be done separately for each power plant (at a cost of $5 million)
but we give typical results here: A fuel melt-down might be expected once
in 20,000 years of reactor operation. In 2 out of 3 melt-downs there would
be no deaths, in 1 out of 5 there would be over 1000 deaths, and in 1
out of 100,000 there would be 50,000 deaths. The average for all meltdowns
would be 400 deaths. Since air pollution from coal burning is estimated
to be causing 10,000 deaths per year, there would have to be 25 melt-downs
each year for nuclear power to be as dangerous as coal burning.

Of course deaths from coal burning air pollution
are not noticeable, but the same is true for the cancer deaths from reactor
accidents. In the worst accident considered, expected once in 100,000
melt-downs (once in 2 billion years of reactor operation), the cancer
deaths would be among 10 million people, increasing their cancer risk
typically from 20% (the current U.S. average) to 20.5%. This is much less
than the geographical variation--- 22% in New England to 17% in the Rocky
Mountain states.

Very high radiation doses can destroy body
functions and lead to death within 60 days, but such "noticeable" deaths
would be expected in only 2% of reactor melt-down accidents; there would
be over 100 in 0.2% of meltdowns, and 3500 in 1 out of 100,000 melt-downs.
To date, the largest number of noticeable deaths from coal burning was
in an air pollution incident (London, 1952) where there were 3500 extra
deaths in one week. Of course the nuclear accidents are hypothetical and
there are many much worse hypothetical accidents in other electricity
generation technologies; e.g., there are hydroelectric dams in California
whose sudden failure could cause 200,000 deaths.

Radioactive
Waste

The radioactive waste products from the
nuclear industry must be isolated from contact with people for very long
time periods. The bulk of the radioactivity is contained in the spent
fuel, which is quite small in volume and therefore easily handled with
great care. This "high level waste" will be converted to a rock-like form
and emplaced in the natural habitat of rocks, deep underground. The average
lifetime of a rock in that environment is one billion years. If the waste
behaves like other rock, it is easily shown that the waste generated by
one nuclear power plant will eventually, over millions of years (if there
is no cure found for cancer), cause one death from 50 years of operation.
By comparison, the wastes from coal burning plants that end up in the
ground will eventually cause several thousand deaths from generating the
same amount of electricity.

The much larger volume of much less radioactive
(low level) waste from nuclear plants will be buried at shallow depths
(typically 20 feet) in soil. If we assume that this material immediately
becomes dispersed through the soil between the surface and ground water
depth (despite elaborate measures to maintain waste package integrity)
and behaves like the same materials that are present naturally in soil
(there is extensive evidence confirming such behavior), the death toll
from this low level waste would be 5% of that from the high level waste
discussed in the previous paragraph.

Other Radiation
Problems

The effects of routine releases of radioactivity
from nuclear plants depend somewhat on how the spent fuel is handled.
A typical estimate is that they may reduce our life expectancy by 15 minutes.

Potential problems from accidents in transport
of radioactive materials are largely neutralized by elaborate packaging.
A great deal of such transport has taken place over the past 50 years
and there have been numerous accidents, including fatal ones. However,
from all of these accidents combined, there is less than a 1% chance that
even a single death will ever result from radiation exposure. Probabilistic
risk analyses indicate that we can expect less than one death per century
in U.S. from this source.

Mining uranium to fuel nuclear power plants
leaves "mill tailings", the residues from chemical processing of the ore,
which lead to radon exposures to the public. However, these effects are
grossly over-compensated by the fact that mining uranium out of the ground
reduces future radon exposures. By comparison, coal burning leaves ashes
that increase future radon exposures. The all-inclusive estimates of radon
effects are that one nuclear power plant operating for one year will eventually
avert a few hundred deaths, while an equivalent coal burning
plant will eventually cause 30 deaths.